Pentane-1,2-diol

Acute Toxicity: inhalation

Administrative data

Endpoint:

acute toxicity: inhalation

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1982

Report date:

1982

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 403 (Acute Inhalation Toxicity)

GLP compliance:

no

Test type:

standard acute method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Pentane-1,2-diol

EC Number:

226-285-3

EC Name:

Pentane-1,2-diol

Cas Number:

5343-92-0

Molecular formula:

C5H12O2

IUPAC Name:

pentane-1,2-diol

Test animals

Species:

rat

Strain:

other: Tif:RAIf(SPF)

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Weight at study initiation: 223 g +/- 8 g (males) and 210 g +/- 14 g (female)
- Housing: rats were group-housed (5 animals per cage) in Macrolon cages type 4
- Diet: ad libitum
- Water: ad libitum

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22°C +/- 2°C
- Humidity (%): 55 % +/- 15 %
- Photoperiod (hrs dark / hrs light): 12 hour/day light cycle

Administration / exposure

Route of administration:

inhalation: aerosol

Type of inhalation exposure:

nose only

Vehicle:

air

Details on inhalation exposure:

GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus:a nose-only exposure system with a plexiglass exposure chamber
- Exposure chamber volume: 100 l
- Method of holding animals in test chamber: For the inhalation period, the rats were placed in individual PVC-tubes positioned radially around the exposure chamber, so that only the snouts and nostrils of the animals were exposed to the aerosol
- System of generating particulates/aerosols: The aerosol was generated by injecting the liquid test substance with a Perfusor IV Syringe Systes (Bender and Hobein, 8051 Zuerich, Switzerland) at a rate of 60 and 180 ml/h into a spray nozzle (JATO, Luzern, Switzerland) . Through the nozzle, compressed filtered air ( 2 atmospheres, 10 l/min ) was discharged into the inhalation chamber. The control animals were exposed to filtered air under the same conditions as described above
- Method of particle size determination: Particle size analysis was conducted twice during each exposure, using a 4 Stage Cascade Impactor with Selectron filters of 25 mm diameter and a pore size of 0.2 µm. The air flow rate for the measurements was adjusted to 17.5 l/min. The amount of particles in the four size classes was determined gravimetrically, and the particle size distribution was calculated and plotted with a desktop computer
- Treatment of exhaust air: exhaust air was decontaminated by subsequent passage through two gas washing bottles containing 5 % NaOH

TEST ATMOSPHERE
- Brief description of analytical method used: The air flow through the chamber was measured with a Brooks Sho-Rate flow meter. Adjustments to maintain a flow of 10 Umin (0.6 m3/h) could be made with a needle valve. However, in all 2 exposures, no deviations were observed, once the equilibrium was reached (within the first 10 minutes). The aerosol concentration in the chamber was determined 5 times (after 30 minutes , 1, 2, 3 , and 4 hours of exposure) by gravimetric sampling of the test atmosphere through a Selectron filter of 50 mm dimeter and a pore size of 0.2 µm. The air flow rate for the sample collection was 10 l/min. The means and standard deviations of the aerosol concentration for each exposure were calculated ,

Analytical verification of test atmosphere concentrations:

yes

Duration of exposure:

4 h

Concentrations:

3380 mg/m3
7015 mg/m3

No. of animals per sex per dose:

10 male + 10 female animals per dose

Control animals:

yes

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Animals were examined for clinical symptoms and mortalities during the exposure at 1, 2, and 4 hours, as well as 2 hours after the exposure and daily thereafter for 14 days. Body weights were recorded immediately prior to exposure and on days 7 and 14 of the observation period.
- Necropsy of survivors performed: yes
- Other examinations performed: clinical signs, body weight,organ weights, histopathology, other: Gross pathological examinations were performed on all animals dying within the 14 day observation period as well as the survivors which were killed after 14 days by asphyxiation with C02. Particular attention was given to the respiratory tract.

Statistics:

Inhalation LC50 values including their 95% confidence limits during the 4-hour treatment and the 14 days post-exposure period could not be calculated , because no mortalities were elicited by the test substance. The body weights of the treated animals and the controls were compared by analysis of variance.

Results and discussion

Effect levels

Sex:

male/female

Dose descriptor:

LC50

Effect level:

> 7 015 mg/m³ air

Based on:

test mat.

Exp. duration:

4 h

Mortality:

no mortality

Clinical signs:

other: Exposure to 3380 mg/m3 resulted in slight , to 7015 mg/m3 in moderate dyspnoea. Ruffled fur and curved body position were seen at both concentrations during the exposure and one day thereafter. All animals exposed t o the test material recovered within 1

Body weight:

The body weight gains of both sexes showed a significant increase during the first observation period (day 1-7). During the second observation period, they were within normal limits.

Gross pathology:

Some of the animals exposed to the test substance exhibited mottled or reddish lungs. No other treatment-related deviations were seen.

Applicant's summary and conclusion

Interpretation of results:

study cannot be used for classification

Remarks:

Migrated information

Conclusions:

Upon a 4 hour aerosol exposure and a 14 day post-treatment observation period , no mortalities could be elicited upon exposure to the test item even at the highest particle concentration tested (7015 mg/m3).
It can be assumed from the absence of mortalities and the weak symptoms observed that the LC50 is above 7015 mg/m3